The present invention relates generally to diagnostic assay systems and methods thereof that are capable of conducting and recording assays in a simple and reliable manner.
A wide variety of systems and approaches exist which allow the occurrence and recording of luminescent reactions, such as of the chemiluminescent or fluorescent types for qualitative and quantitative results. One class of analytical instruments typically used in this field is referred to as luminometers. Luminometers conduct and record luminescent reactions generated, for instance, by a biological test fluid sample that contains a reagent of interest, such as an analyte, and a reagent in an assay element. Examples of these approaches include single-sample luminometers fitted with photographic multipliers; single-sample luminometers fitted with solid-state detectors; multiple sample luminometers; automatic luminometers with imaging systems based on CCD cameras; and photographic camera type luminometers. Some of the foregoing devices using photographic films of the conventional and self-developing type for recording luminescent activity are described in, for example, U.S. Pat. Nos.: 4,863,689; 5,035,866; and, 5,188,965. Heretofore known prior art tends to be limited in a number of ways, such as being expensive due to the relatively expensive electronics required, training of personnel required because of their relatively complicated nature, and being relatively cumbersome in use and expensive in construction. In addition, the prior art contains many devices that deliver a solution containing an analyte of interest to a testing solution for generating a luminescent read-out signal that indicates the presence of an analyte of interest. It is important in conducting these assays for the solution containing such an analyte to be delivered to a testing solution in a manner that enhances the reliability of the testing. One known testing device is commercially available from Biotrace, Inc., Plainsboro, N.J. that uses a pick-up device or swab having testing rings that swipe a surface to be tested. The ampoule includes a generally hollow tubular housing for slidably receiving the pick-up device. The ampoule is transparent, and has an open end portion that is adapted to receive the sample pick-up, and a closed end portion that is transparent whereby luminescent activity can form a latent image on a recording film. A sealing membrane is located generally transversely to the ampoule housing to define a chamber or reservoir with the closed end portion to sealingly accommodate an assay fluid therein. The sealing membrane is made of a thin-walled metallic material that is impervious to fluid and ambient atmosphere. The sealing membrane is adapted to be punctured by the sample pick-up device when the latter is inserted by an operator therethrough. The assay fluid can be one that generates a chemiluminescent signal in response to a reagent, such as ATP (Adenosine Triphosphate) being present on the sampling rings. ATP is used as an indicator of the presence of organic debris, such as microorganisms. The sample pick-up device includes a handle, a stem, and a plurality of laterally extending sampling rings. The sampling rings are used to engage a surface to be tested for microorganisms. A user merely rubs the rings against a surface to be tested, for instance, a food preparation surface and inserts the sampling ring into and through the membrane, whereupon the rings are immersed into the assay fluid. If ATP is present, in significant amounts on the sampling rings, it will react with the reagent in the fluid and generate a luminescent read-out signal that is recordable on the film.
Despite the existence of a wide variety of known diagnostic luminescent type testing systems and approaches, however, it is, nevertheless, desired to improve upon the overall ease, versatility, and reliability of such systems and their testing procedures, as well as reduce overall costs associated with their construction and use.
In accordance with the present invention, provision is made for a diagnostic assay system for conducting a luminescent test and recording luminescent signals generated thereby on an image recording material. Included in the system is a light-tight housing assembly including a base and a cover member; an image recording system coupled to the base including an image recording medium for recording lumuinescent reactions thereon; an assembly for holding at least one chemical implementation device mounted in the base wherein the assembly allows a bottom of the implementation device to be in juxtaposed relationship to an image recording medium; a shutter mechanism movable between non-exposing and exposing positions in response to an operator moving the shutter mechanism; and, a biasing device for automatically returning the shutter mechanism to the non-exposing condition from the exposing condition.
In an illustrated embodiment the system includes a locking assembly for locking the shutter mechanism in the exposing condition and a timing mechanism coupled to the locking assembly that is operable for releasing the shutter mechanism after a preselected period of time.
In accordance with another preferred aspect of the present invention, provision is, preferably, made for a hand-held, portable diagnostic assay system. The system is operable for conducting and recording luminescent reactions, that generate luminescent signals, such as chemiluminescent and fluorescent signals, that are recordable an image recording medium, such as a film assemblage of the self-developing type. Included in the system, in one embodiment, is a housing assembly defining a light-tight enclosure carrying at least the film unit and an exposure opening that optically communicates the film unit and the luminescent read-out signal. A film processing unit in the housing is operable for processing exposed self-developing film units passing therethrough. Provision is made for a sample carrier means or assembly that has one condition for receiving a luminescent testing assembly and a second condition for exposing the film. The sample carrier assembly can carry, in a light-tight manner, at least one luminescent testing assembly that is capable of generating a luminescent read-out signal recordable on the image recording medium in response to the testing assembly being actuated. Whenever the sample carrier is in the second condition, the generated signal exposes the film unit. Developing the resultant latent image is initiated when the film unit is advanced from the housing after passing through the film processing unit.
In an illustrated preferred embodiment, the sample carrier has an opening for receiving a test container of the luminescent testing assembly. The test container comprises a reservoir that stores a luminescent testing means; which in a preferred embodiment is in the form of a fluid that is sealed by means of a sealing device. A portion of the reservoir is transparent for allowing transmission of the generated read-out signal to the film through an open exposure opening. A sampling device of the luminescent testing assembly can sample a surface to be tested and is inserted, in a light-tight manner, within the test container such that a portion thereof is immersed in the fluid. If the sampling device contains a reagent that reacts with a reagent in the assay fluid, the generated luminescent signal can expose the film through the open exposure opening and transparent portion. In this embodiment, movement of the sample carrier carrying the luminescent testing assembly opens the exposure opening and registers the transparent reservoir portion therewith for exposing the film. Movement of the sample carrier back to the receiving position closes the exposure opening. Further in another illustrated embodiment, the test container includes opaque means therein which serves, when the container is held in the sample carrier, to block ambient light from reaching the exposure opening.
In another illustrated preferred embodiment, provision is made for effecting and recording a luminescent read-out signal of a control test generally simultaneously with a luminescent signal of the test sample.
In an illustrated embodiment, a sample carrier assembly carries a luminescent sample test assembly and a luminescent control test assembly. Fluid transfer means, such as light-tight capillary grooves, allow transfer of the control and test fluids from separate ports therefor to the respective test assemblies. When the sample carrier is inserted into a recess in a processor housing containing the film, a shattering mechanism is opened which allows luminescent read-out signals emitted from the test sample and control luminescent testing assemblies to respectively expose the film. Removal of the sample carrier from the processor housing closes the shutter. The film can be advanced as indicated above in the other embodiments.
In still another illustrated embodiment of the present invention, provision is made for a means and method for achieving a quantification of the luminescent signal generated and recorded on the film. In one such embodiment, such quantification is achieved by reason of an optical filter. The filter can have alternating light attenuating zones, such as transparent and opaque zones that act to delineate different sized read-out signals. The different sized images correlate to corresponding different test results. Because of the light attenuation, different sized luminescent images will be visible through correspondingly different sized attenuation zones; thereby providing a visual measurement of the test results. In yet other embodiments, the quantification can be obtained by pre-exposing the film with a gradation of different sized images. The different sizes correspond to different predetermined outputs of the luminescent signals. Alternately, provision is for a film overlay comprising a series of different sized images thereon with each overlay image corresponding to different test outputs. In use the test image that is captured during the actual test can be compared to images on the overlay for quantifying the test result.
Methods are contemplated for conducting and recording read-out signals that can expose the image recording material.
It is an object of the present invention to provide an improved method and system for conducting and recording luminescent reactions, wherein the results can be immediately and reliably ascertained by an operator.
It is another object of the present invention to provide an improved method and system for conducting and recording luminescent reactions in a hand-held assay processor using self-developing type film.
It is another object of the present invention to provide an improved method and system of the last noted types for conducting and recording multiple sample tests.
It is another object of the present invention to provide an improved method and system for conducting and recording luminescent reactions in a hand-held assay processor wherein both test sample and control fluids are applied to corresponding different test strips.
It is another object of the present invention to provide an improved method and system of the last noted types for conducting and recording luminescent reactions wherein the output signals are recorded on film and quantified.
It is another object of the present invention to detect the luminescent signals electronically and print relevant information on the film.
It is another object of the present invention to provide for an improved method and system which is simple and reliable to operate and which is low-cost in cost.
The above and other objects and features of the present invention will become apparent when reading the following description taken conjunction with the accompanying drawings wherein like parts are indicated by like reference numerals throughout the several views.